Flip-chip bonding is a technique for directly bonding bumps of a semiconductor chip onto pads of a substrate in order to mount the semiconductor chip onto the substrate. With flip-chip bonding, bumps of a semiconductor chip are typically aligned to pads of a substrate and the bumps of the semiconductor chip are then pressed to the pads of the substrate and heated to melt them together, whereby the bumps of the semiconductor chip are bonded to the pads of the substrate.
Techniques of using anisotropic conductive film for flip-chip bonding are being put to practical use. The anisotropic conductive film, or ACF, is a bonding material made of resin, such as epoxy, that contains conductive particles. With flip-chip bonding by use of anisotropic conductive film, the anisotropic conductive film is attached to a bonding surface of the substrate in contact with the semiconductor chip; the bumps of the semiconductor chip are aligned to the pads of the substrate; the bumps of the semiconductor chip are then pressed against the pads of the substrate to secure electrical contact between the bumps and pads; and the anisotropic conductive film is heated and cured, thereby anchoring the bumps of the semiconductor chip to the pads of the substrate.
However, with flip-chip bonding by use of such anisotropic conductive film, if the pressure applied to press the bumps of the semiconductor chip to the pads of the substrate is insufficient, sufficient electrical contact between the bumps and pads is not obtained; on the other hand, if the pressure is excessive, the substrate may be damaged. If heating is insufficient or excessive, the resin would not be cured with sufficient residual stress maintained after the pressure is released. In this way, the problem is that it is difficult to provide optimum pressure and heating for flip-chip bonding by use of such bonding material.
Accordingly, it is an object of the present invention to provide an optimum condition detection method for flip-chip bonding that permits simple detection of pressure and heating temperature most suited for flip-chip bonding by use of bonding material.